To obtain excellent laser quality and light utilization efficiency without increasing costs.

The light source unit 10 is provided with a semiconductor laser module 10A including a semiconductor laser 10a, and an optical module 10B including a half mirror 10c, a collimator lens 10d and an aperture plate 10e. Light emitted from the surface emitting laser array chip of the semiconductor laser 10a is made incident on the half mirror 10c through only an air layer, and the light transmitted through the half mirror 10c is outputted from the light source unit 10 through the collimator lens 10d and the aperture plate 10e. In such a manner, the light emitted from the surface emitting laser array chip is directly made incident on the optical module 10B without interposing a sealing glass material or the like.